BENEFIT PLANS (Tables)

6 Months Ended

Jun. 30, 2026

Retirement Benefits [Abstract]

Schedule of Components of Net Periodic Benefit Cost

Pension Plans

Three Months Ended June 30, 2026	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	26	$	3	$	3	$	2	$	3	$	1	$	3
Interest Cost	52		4		6		6		4		2		3
Expected Return on Plan Assets	(63)		(5)		(8)		(8)		(7)		(3)		(3)
Amortization of Net Actuarial Loss	11		1		1		1		1		1		—
Settlements (a)	4		(4)		—		—		—		4		—
Net Periodic Benefit Cost (Credit)	$	30	$	(1)	$	2	$	1	$	1	$	5	$	3

Three Months Ended June 30, 2025	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	24	$	2	$	2	$	2	$	3	$	2	$	2
Interest Cost	53		4		7		7		4		2		3
Expected Return on Plan Assets	(71)		(5)		(10)		(10)		(8)		(3)		(3)
Amortization of Net Actuarial Loss	4		1		—		1		1		—		—
Net Periodic Benefit Cost (Credit)	$	10	$	2	$	(1)	$	—	$	—	$	1	$	2

Six Months Ended June 30, 2026	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	51	$	5	$	5	$	5	$	5	$	3	$	5
Interest Cost	103		8		12		12		9		5		6
Expected Return on Plan Assets	(128)		(10)		(16)		(16)		(13)		(7)		(7)
Amortization of Net Actuarial Loss	21		2		2		2		2		1		1
Settlements (a)	(7)		(8)		—		—		(6)		4		—
Net Periodic Benefit Cost (Credit)	$	40	$	(3)	$	3	$	3	$	(3)	$	6	$	5

Six Months Ended June 30, 2025	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	48	$	4	$	4	$	5	$	5	$	3	$	4
Interest Cost	106		9		13		13		9		5		6
Expected Return on Plan Assets	(141)		(11)		(19)		(19)		(15)		(7)		(7)
Amortization of Net Actuarial Loss	8		1		1		1		1		—		—
Net Periodic Benefit Cost (Credit)	$	21	$	3	$	(1)	$	—	$	—	$	1	$	3

(a)Represents deferrals of regulatory activity.

OPEB

Three Months Ended June 30, 2026	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	1	$	—	$	—	$	—	$	—	$	—	$	—
Interest Cost	7		—		1		1		1		1		—
Expected Return on Plan Assets	(30)		(2)		(4)		(3)		(2)		(2)		(2)
Amortization of Prior Service Credit	—		—		—		—		—		—		—
Amortization of Net Actuarial Gain	—		—		—		—		—		—		—
Net Periodic Benefit Credit	$	(22)	$	(2)	$	(3)	$	(2)	$	(1)	$	(1)	$	(2)

Three Months Ended June 30, 2025	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	1	$	1	$	—	$	—	$	—	$	—	$	—
Interest Cost	9		—		2		1		1		1		—
Expected Return on Plan Assets	(28)		(2)		(5)		(4)		(3)		(2)		(2)
Amortization of Prior Service Credit	(1)		—		—		—		—		—		—
Net Periodic Benefit Credit	$	(19)	$	(1)	$	(3)	$	(3)	$	(2)	$	(1)	$	(2)

Six Months Ended June 30, 2026	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	2	$	—	$	—	$	—	$	—	$	—	$	—
Interest Cost	15		1		2		2		1		1		1
Expected Return on Plan Assets	(59)		(5)		(8)		(7)		(5)		(3)		(4)
Amortization of Prior Service Credit	(1)		—		—		—		—		—		—
Amortization of Net Actuarial Gain	(1)		—		—		—		—		—		—
Net Periodic Benefit Credit	$	(44)	$	(4)	$	(6)	$	(5)	$	(4)	$	(2)	$	(3)

Six Months Ended June 30, 2025	AEP		AEP Texas		APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Service Cost	$	2	$	1	$	—	$	—	$	—	$	—	$	—
Interest Cost	17		1		3		2		2		1		1
Expected Return on Plan Assets	(56)		(5)		(9)		(7)		(6)		(3)		(4)
Amortization of Prior Service Credit	(1)		—		—		—		—		—		—
Amortization of Net Actuarial Loss	(1)		—		—		—		—		—		—
Net Periodic Benefit Credit	$	(39)	$	(3)	$	(6)	$	(5)	$	(4)	$	(2)	$	(3)

Qualified Pension Contribution

The following table provides details of the contribution by Registrant:

Company	Qualified Pension Plan
	(in millions)
AEP	$	95
AEP Texas	12
APCo	—
I&M	2
PSO	1
SWEPCo	9